vim-patch:9.0.0197: astro files are not detected (#19755)

Problem:    Astro files are not detected.
Solution:   Add a pattern to match Astro files. (Emilia Zapata, closes vim/vim#10904)
6a76e84f55

runtime/lua/vim/filetype.lua

@@ -142,6 +142,7 @@ local extension = {
   asp = function(path, bufnr)
     return require('vim.filetype.detect').asp(bufnr)
   end,
+  astro = 'astro',
   atl = 'atlas',
   as = 'atlas',
   ahk = 'autohotkey',